CENTERVILLE — When the set is entirely digital, it’s even more important for actors to hit their marks.

Cast and crewmembers from all over the world flew to Centerville this month to do principal filming for the upcoming Tex Murphy video game, “Project Fedora.” Local developer Big Finish Games is behind the project, which combines full-motion video with fully explorable 3D game environments.

“We’re really trying to give it the feel of an interactive movie,” said Chris Jones, one of the game’s creators and the actor playing Tex Murphy.

As part of that, the team filmed hundreds of different scenes that show different conversations and results that stem from character’s choices in the game.

“You have the same set of characters, but the player has the opportunity to take it in many different directions,” Jones said. “As you take the character down one path or the other, you’ll learn things you wouldn’t on a different path.”

For the actors, however, every path was the same uniform shade of green. All of the scenes were filmed in front of a green screen. Later, that green would be replaced by the same 3D background and props used in the playable sequences.

“It’s like playing pretend when you’re a kid,” said actress Jodi Russell, who plays Taylor in the game. “You have no set, and you have no props, so you have to use your imagination.”

For the director, the challenge is even bigger. Lighting on a green screen set must match the lighting sources in the 3D environment so the shadows will fall correctly on the actor’s faces. Actor placement must also be exact С the director needs to keep both framing and details of the future set in mind.

“It’s a blank void behind them, but in my mind it’s an abandoned airport with the fog settling in,” said director Adrian Carr.

During filming, he often keeps one eye on the actors and another eye on a computer screen that shows him what the camera is seeing.

“The actors place a lot of trust in my vision, because it’s so disorienting,” said Carr. “It’s like working in a vacuum.”

That vacuum gets filled in later, likely by Mat Van Rhoon. As the editor and digital compositor for “Project Fedora,” Van Rhoon is responsible for making it look as if the real actors belong in their digital environments.

“It all comes down to the tiny details,” he said.

Some of those details include creating an artificial focus point for the shot so that elements fade out as they would on camera. He also makes sure the computerized light spills onto the real actors.

“You’re trying to re-create the director’s vision,” Van Rhoon said. “You have to go back and pay homage to everything that was considered in the original shot.”